Penn State Extension announced on May 27 that preparations are underway for the 2026 trapping season, with plans to operate 31 monitoring sites statewide reporting weekly counts of corn earworm and fall armyworm. Currently, five sites have begun reporting, all detecting corn earworm presence. Most locations reported low numbers; however, Waynesboro in Franklin County recorded 21 moths.
During the 2024 and 2025 growing seasons, unusually early and high peaks in corn earworm flights were observed in June, which caught some growers by surprise. Historically, corn earworm has not overwintered in Pennsylvania. Ongoing studies aim to determine if these early moths are migrating from southern regions or emerging from locally overwintering populations—or a combination of both. The report states that another early peak could put early planted sweet corn at particular risk due to limited alternative hosts available in June. Early monitoring efforts in New York, New Jersey, and Maryland have also consistently detected moth captures.
Maps and graphics provided by Penn State Extension will update as new reports arrive from across the state. Weekly trap catches for both pests can be viewed on an interactive map showing historical data alongside current-season results. Spray intervals are indicated by color-coded points based on weekly trap catch numbers.
Threshold guidelines for spray frequency based on weekly corn earworm trap catches range from very low (14-35 per week) to high (over 350 per week), dictating intervals between two and seven days depending on severity. Tables display recent weeks’ average catches when data is available; trend figures compare current year averages with those of previous years.
Statewide trends for both pests—including average weekly trap counts—are tracked throughout the season using updated figures as new information becomes available.
Penn State Extension delivers science-based education focused on agriculture, food safety, resource management, nutrition, and environmental stewardship through local offices and digital tools across every county in Pennsylvania; it also collaborates with government agencies and offers workshops addressing issues such as farming practices and pest control, according to the official website.
